Unique Rhythm Method

I remember reading this in a guitar magazine as told by Steve Vai. He mentions that sometimes in order to create musical sentences for guitar he would sing then interpret it onto the guitar. I imagine he would sing a group of notes or maybe a known song and use that to develop a rhythmic passage of notes on guitar. This may be an old method, but perhaps not everyone knows of it. Useful for those who have a hard time thinking of a rhythm of notes.